1 0 0 0 OA ゲジの発育段階
The author tried to breed a Japanese house centipede, Thereuonema hilgendorfi Verhoeff and examined its postembryonic development on the basis of the passed number of molting. 1. The eggs are creamy yellow, subspherical, and covered with microscopic hairs which are helpful to moisten rapidly the surface of eggs by a little water in the soil. Each egg has a diameter of 1mm and the length of 1.2mm, its shell being about 40μ tick. All eggs are not laid in masses. The embryos bear four pairs of legs, four tergits and two zonular tergits of maxillary segments and prehensors. Their eyes are pigmented compound. 2. The six larval stadia, as summarized in Table 1, can be distinguished by differences in pairs of legs. Larvae of each stadium bear the embryonic tergits, sternits and limb buds on the mesodermic somite. After the sixth molting, larvae come into Agenitalis-stadium. 3. The epimorphic developmental period is divided into six stadia and these have the relation to the passed number of molting as follows: No. of molting Body size Agenitalis I: 6 7.5-9.0mm. length Agenitalis II: 7 8.5-10.5mm. length Immaturus: 8 10.5-13mm. length Praematurus: 9 11.5-14.5mm. length Pseudomaturus: from 10 to 12 12-20mm. length Maturus: from 13 to 17 19-28mm. length 4. The Hemianamorphic development of T. hilgendorfi is divided into twelve stadia. Of those stadia, Pseudomaturus and Maturus pass through three and five times moltings respectively, while the others one molting.
1 0 0 0 OA 日本産普通多足類の後胚発生 : II.カマクラオオゲジ
1) The hemianamorphic development of the Japanese house centipide, Thereuopoda ferox VERH., is divided into eleven or twelve growing stadia which have the morphological characters as are shown in Table 1. 2) Adult bears numerous spines on each segment of legs and on the flagellum primum of antennae. Growth of spines has relations to growing stadia as shown in Table 2.
1 0 0 0 OA 日本産普通多足類の後胚発生 : I.ゲジにおける有歩肢胴節の改形的発育とその背板の問題
Several reports concerning the tergite of Scutigeridae have already been published since the old study of Latzel (1880). This paper gives a new aspect on the tergite. The materials used for the observation are the two following species, Thereuonema hilgendorfi Verhoeff and Thereuopoda ferox Verh. The results obtained are as follows: 1.Scutigeridae has a small covered tergite between any comsecutive two of eight main tergites. If these seven small tergites are regarded to be the modification of the main tergites, the tergites of the family are fifteen in number and this number coincides with that of the pairs of legs. (see Figs. 1-4) 2.The earlier workers except Verhoeff made a common error which denied the presence of a small covered tergite between the seventh and the eighth main tergite because of seeing Scutigefidae in a relation to Lithobiidae. Attems ('30) has mistaken a pretergite as a small covered tergite. 3.The anamorphic development of leg-bearing segments is summarized in the Table 1. So far as the present writer has observed, there is found no foundation of Verhoeff's theory that the main tergite of Scutigeridae is a diplotergite. It is considered that the eight main tergites belong to the odd leg-bearing segments, and that each of the even segments has a small covered tergite. These small tergites appear at the epimorphic development period. 4.In the Table 1, doubly marked tergites have the following characteristic: each of them is a normally complished tergite at the earlier stage of the stadium, but at the later stage it turns into a cuticula by partial moulting which occurs before the change of larval stadia. This is thought to be an organic phenomenon for the formation of the two new pairs of legs in the embryonic somite. As compared with each other between Verhoeff's Table and the present writer's, it is likely that the former has considered this characteristic process as a change of teloptergite into diplotergite. 5.The "Telotergite" called by Verhoeff means the embryonic tergite at the first and the second larval stadium and also means the complished tergite, which turns into cuticula as mentioned above, at the other stadia. Thus, it must be said that he put heterogenous tergites in the same category.
1 0 0 0 OA 日本産普通多足類の後胚発生XXI. : タメトモヤスデ科の1新属とクビヤスデ科の1新種
1. Dimorphodesmus, gen. nov. Related to Eucondylodesmus and Kylindogaster but is distinguished from these genera by the number of body segments, the shape of tubercles on the metatergites, and in having a modification on the anal segment of the abult male. In number of body segments it is near Doratodesmus (Jeekel, 1955) but differs in that the metatergites are without mid-dorsal processes. Body composed of 19 segments in the male and 20 in the female. The segments with low and rounded tubercles, which are arranged in 2 series on each of most metatergites. In the adult male the posterior margin of the anal seegment is modified in a peak-shape. The structure of male gonopods are clear. Telopodit distad of prefemur is broadened and lamellate, the femur with a process on the distal side, and tibiotarsus with some acute processes. Type species: Dimorphodesmus peculiaris, sp. nov. Dimorphodesmus peculiaris sp. nov. General color pale brown, the antennae whitish. Length about 4 mm in male, 5 mm in female. Head and antennae are very similar to those of Eucondylodesmus. Collum is subtrapezoid, narrower than the next segment, the upper irregularly granulate, and lateral angle areas conspicuously tuberculate. The second tergite is flattend and narrow at the middle dorsum, with three series of tubercles laterally. The keels are greatly enlarged and with 4 large, unequal scutellated tubercles. Third and fourth deels are simple and anterior margin serrulated. The succeeding keels are moderately enlarged, but the penult keels are conspicuously reduced in adult male. All keels with a incision on each of the posterior margin, and lateral ends of typical keels indistinctly 2-1obed. Repugunatorial pores open on the central tubercles of the keels of segments 5, 7, 10, 12, 13 and 15-18 (19 in female). Anal tergite of female is triangular and with tubercles. In adult male it is steep dome-shaped, smooth and with a post-marginal L-shaped peak in. The peak is as illustrated in figures 1 and 2. Gonopods as figured (Fig. 1, I-K). The femoral process shows some minute individual variations in length and shape, and seminal groove runs in the base of the process. Holotype: 1♂ (4.2 mm in Length); Allotype: 1♀ (5.0 mm in Length); Other specimens 7 ♂, 12♀. All the types collected by the author. Type locality: Oshima, Niihama, Ehime Pref. Through May 1964. Other record: Kinsha, Iyo-Mishima, Ehime Pref. May 17, 1963. Types are preserved in the author's collection. 2. Archandrodesmus kumamotensis, sp. nov. This species is distinguished from the related A. japanicus by the details of the male gonopods. Colour in life cinnabar-red. Length about 5 mm in male, 5.5 mm in female. Somatic characters are as described for A. japonicus, but without nodules of tarsal setae on the last two pairs of legs. Male gonopod is small, granulated, with two prefemoral branches, a leaf-shaped tibiotarsus and a ligulate branch. Figure 3 shows a different view of the left gonopod. Holotype: 1♀ (5 mm in Length); Allotype 1♀ (about 5.5 mm in Length). 7 other specimens. All types are collected by the author. Type locality: The remins of Kumamoto Castle, Kumamoto Pref., Aug. 10, 1964. Types are preserved in the author's collection.
1 0 0 0 OA 日本産普通多足類の後胚発生 : X ヤケヤスデの生活史
The life history of Oxidus gracilis was observed at Niihama district (Ehime Prefecture, Japan) during the year 1959 and 1961. The results were as follows: 1. The animals pass through seven larval stadia and sexual maturity occurs in the eighth stadium. Sex differentiation takes place in the larvae of the fourth stadium. Male animals develop a pair of very minute gonopod-bud appears at the position where the eighth legs had grown in the former stadia. The gonopod-bud scarcely grows during the stadia from the fifth to the seventh. However, it changes abruptly to a pair of complete gonopods at the eighth stadium. 2. The animals may be divided into two strains according to their breeding season. a) Strain breeding in Spring: The adults begin to crawl out of hibernation in early spring, and lay eggs from April to May. The larvae of this strain become adult at the end of November and then hibernate. b) Strain breeding in Autumn: The animals hibernate at various larval stadia as the fifth, the sixth or the seventh, and become mature in the early summer of the nest year, and lay eggs in autumn.